Acute flaccid paralysis (AFP)

Acute Flaccid Paralysis (AFP)

1. Acute Flaccid Paralysis (AFP) BY: Azad A Haleem DCH. FIBMS University of Duhok , College of Medicine Heevi Pediatrics Teaching Hospital [email protected] 2014

2. Objectives Definition of AFP Differential Diagnosis of AFP SURVEILLANCE Protocol for AFP surveillance Certification (polio free) Epidemiology Clinical approach to children with AFP How to differentiate among (Polio, Guillain - Barré syndrome, Traumatic neuritis, Transverse Myelitis )

3. Definition of AFP sudden onset of weakness or paralysis in a previously normal limb over a period of 15 days in a patient aged less than 15 years age. It is a Lower motor neurone lesion

4. Differential Diagnosis of AFP SPINAL CORD Anterior horn cell disease PERIPHERAL NERVE Disorders of neuromuscular transmission MUSCLE Systemic disease

5. SPINAL CORD Demyelinating diseases transverse myelitis Cord compression tumour trauma paraspinal abscess haematoma vascular malformation with thrombosis/bleeding Ischaemic cord damage spinal cord stroke anterior spinal artery syndrome peri -operative complication Differential Diagnosis of AFP

6. Anterior horn cell disease Acute poliomyelitis Vaccine-associated paralytic polio Other neurotropic viruses ( eg . enteroviruses and herpes viruses) Differential Diagnosis of AFP

7. PERIPHERAL NERVE Unilateral : Enteroviral infection local trauma Focal mononeuropathy Bilateral: Guillain Barré syndrome Acute toxic neuropathies (heavy metals, snake toxin) Neuropathies of infectious diseases (diphtheria) Differential Diagnosis of AFP

8. Disorders of neuromuscular transmission Myasthenia gravis Botulism Insecticide (organophosphate poisoning) Tick bite paralysis Snake bite Differential Diagnosis of AFP

9. MUSCLE Polymyositis post viral myositis periodic paralysis toxic myositis ( Corticosteriods and blocking agents) Mitochondrial diseases (infantile type) Differential Diagnosis of AFP

10. Systemic disease Acute porphyrias Critical illness neuropathy Acute myopathy in ICU patients Differential Diagnosis of AFP

11. Investigations Spinal cord MRI. CSF study. Nerve conduction study. OTHERS

12. SURVEILLANCE Surveillance is the collection, analysis, interpretation and dissemination of information about a selected health event. Health officials use the information to plan, implement and evaluate health programs and activities.

13. AFP surveillance in children To do this we have to report enough cases, send stools for enterovirus isolation using a standardised protocol, and follow up children with AFP to determine the outcome.

14. AFP surveillance in children The non-polio AFP rate is an indicator of surveillance “sensitivity”. If it is < 1/100 000 CHILDREN below age 15 per year then the surveillance system is probably missing cases of AFP. Adequate stool specimens collected from ≥80% of AFP cases.

15. Protocol for AFP surveillance Step Timing Description Case Detection at diagnosis Follow case definition for AFP Case Reporting ≤ 48 hours of report Tel: Timing of stool specimens within 2 weeks of onset of paralysis 2 stool specimens collected no less than 24 hours apart . Collection of specimens Fresh stool, or rectal swabs containing fecal material (at least 8g – size of an adult thumb). Place in a sterile glass bottle Transport of Stools as soon as able. Specimens arriving at national laboratory ≤ 3 days of being sent Maintain a cold chain of 2 - 8 ⁰ C. Transport in dry ice if transportation will take > 24 hours Caution: avoid desiccation, leakage; ensure adequate documentation Follow up of patients 60 days from To determine whether there is residual paralysis on follow up

16. Wild polio cases by country in the region for 2013-2014 (ending 06 April 2014) 2013 14 Afghanistan 93 Pakistan 194 Somalia 26 Syria 327 Total 2014 4 Afghanistan 1 Iraq 43 Pakistan 1 Syria 49 Total Epidemiology

17. Certification (polio free) Basic national documentation has been accepted from countries that have been polio-free for 3 years or more. Provisional national documentation for regional certification has been accepted from countries that have been polio-free for 5 years or more and have completed phase I of laboratory containment.

18. Regular yearly updates (annual update and abridged annual update) have been submitted on a yearly basis by all countries whose basic national documentation was accepted ( annual update ), and countries whose final national documentation for regional certification was accepted ( abridged annual update ). 

19. Iraq Annual updates  have been received for years 2002–2006 and accepted. Final national documentation for regional certification  has been submitted, and was accepted in 2008. Abridged annual updates and annual updates have been received and accepted for years 2008–2012.

20. Clinical approach to children with AFP

21. Clinical Questions Demonstrable Lower limb Motor Weakness Sphincters? Preserved Preserved Preserved/ Affected Sensory loss? None None \ ‘Glove & Stocking’ Dermatomal Reflexes? Reduced or normal Absent Absent, reduced or normal Clinical Localisation MUSCLE PERIPHERAL NERVE SPINAL CORD Differential Diagnosis •post viral myositis • periodic paralysis • toxic myositis Unilateral • enteroviral infection • local trauma Bilateral • Guillain Barré syndrome • toxic neuropathy • acute transverse myelitis • spinal cord / extraspinal tumour • arteriovenous malformation • spinal cord stroke • extradural abscess • spinal tuberculosis • spinal arachnoiditis Investigations Required • AFP workup • creatine kinase • serum electrolytes • urine myoglobin Required • AFP workup • Nerve conduction study Optional • MRI Required • AFP workup • CSF: cells, protein • Nerve conduction study • Forced vital capacity Required • AFP workup • URGENT Spinal cord MRI Optional (as per MRI result) • TB workup • CSF : cells, protein, sugar, culture, TB PCR , oligoclonal bands

22. How to differentionate among Polio Guillain-Barré syndrome Traumatic neuritis Transverse Myelitis

23. Polio Guillain-Barré syndrome Traumatic neuritis Transverse myelitis Installation of paralysis 24 to 48 hours onset to full paralysis From hours to ten days From hours to four days from hours to four days Fever at onset High, always present at onset of flaccid paralysis, gone the following day Not common Commonly present before, during and after flaccid paralysis rarely present Flaccid paralysis Acute, usually asymmetrical, principally proximal Generally acute, symmetrical and distal Asymmetrical, acute and affecting only one limb acute, lower limbs, symmetrical Muscle tone Reduced or absent in affected limb Global hypotonia Reduced or absent in affected limb Hypotonia in lower limbs Deep-tendon reflexes Decreased to absent Globally absent Decreased to absent Absent in lower limbs early hyperreflexia late

24. Polio Guillain-Barré syndrome Traumatic neuritis Transverse myelitis Sensation Severe myalgia, backache, no sensory changes Cramps, tingling, hypoanaesthesia of palms and soles Pain in gluteus, hypothermia Anesthesia of lower limbs with sensory level Cranial nerve involvement Only when bulbar involvement is present Often present, affecting nerves VII, IX, X, XI, XII Absent Absent Respiratory insufficiency Only when bulbar involvement is present in severe cases, enhanced by bacterial pneumonia Absent Sometimes Autonomic signs & symptoms Rare Frequent blood pressure alterations, sweating and body temperature fluctuations Hypothermia in affected limb Present Cerebro -spinal fluid Inflammatory Albumin-cytologic dissociation Normal normal or mild increase in cells

25. Polio Guillain-Barré syndrome Traumatic neuritis Transverse myelitis Bladder dysfunction Absent Transient Never Present Nerve conduction Velocity Abnormal: anterior horn cell disease (normal during the first 2 weeks) Abnormal: slowed conduction, decreased motor amplitudes Abnormal: axonal damage normal or abnormal, no diagnostic value EMG Abnormal Normal Normal Normal Sequel at three months and up to a year Severe, asymmetrical atrophy, skeletal deformities developing later Symmetrical atrophy of distal muscles Moderate atrophy, only in affected lower limb flaccid diplegia atrophy after years

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27. Guillain-Barré Syndrome It is an acute idiopathic acquired inflammatory demyelinating polyneuropathy . GBS is the most common cause of acute flaccid paralysis in healthy infants and children.

28. Epidemiology It has an annual incidence of 0.6 to 2.4 cases per 100,000 population and occurs at all ages and in both sexes. Occurs rarely in children younger than two years of age, but can occur in infants. Males are affected approximately 1.5 times more often than females in all age groups.

29. Pathophysiology Immune mediated disease. There is no known genetic factors. Two third of cases follow a respiratory or GI infection. Campylobacter infection is the most common, but other organisms include CMV, EBV, HSV, Enteroviruses ,… Guillain-Barré syndrome has been reported to follow vaccinations epidural anesthesia thrombolytic agents

30. Clinical Features   Usually 2 - 4 weeks following respiratory or GI infection. The classic presentation : Fine paresthesias in the toes and fingertips. Lower extremity weakness: symmetric & ascending. Gait unsteadiness. Inability to walk. Respiratory muscles involvement. Cranial Neuropathy: Facial nerve is most commonly affected, resulting in bilateral facial weakness. Miller Fisher syndrome : triad of external ophthalmoplegia , Ataxia, areflexia with muscle weakness.

31. Clinical Features… cont By the peak of the illness, the frequency of symptoms was as follows: - 79% had neuropathic pain - 60% could not walk - 51% had autonomic dysfunction - 46% had cranial nerve involvement - 24% could not use their arms - 13% required mechanical ventilation

32. Physical Examination Symmetric limb weakness diminished or absent reflexes Vibration and position sensation are affected in 40% of cases. Autonomic dysfunction: Cardiac dysrhythmias . Orthostatic hypotension, hypertension Paralytic ileus Bladder dysfunction

33. Clinical Course  >90% of patients reach the nadir of their function within two to four weeks, with return of function occurring slowly over the course of weeks to months. The clinical course of GBS in children is shorter than in adults and recovery is more complete. In patients who did not require mechanical ventilation, the median time to recovery of independent walking was 43 to 52 days in children compared to 85 days in adults.

34. Forms of GBS  Acute inflammatory demyelinating polyneuropathy (AIDP): the most common form in developed countries. Acute motor axonal neuropathy: more common in developing countries. More severe with common respiratory involvement. Strong association with campylobacter Acute motor-sensory axonal neuropathy  Polyneuritis cranialis : associated with CMV infection

35. Diagnosis Cerebrospinal Fluid: - After the first week of symptoms typically reveals: normal pressures, normal cell count and elevated proteins (greater than 50 mg/dL) - Early in the course (less than one week), protein levels may not yet be elevated, but only rarely do they remain persistently normal Electrophysiologic studies: - Most specific and sensitive tests for diagnosis - Evidence evolving multifocal demyelination - A normal study after several days of symptoms, makes the diagnosis of Guillain-Barré syndrome unlikely.

36. GBS Management Critical care monitoring autonomic and respiratory dysfunction. Children with the following should be admitted to PICU: a. Flaccid quadriparesis b. Rapidly progressive weakness c. Reduced vital capacity ( ≤ 20 mL/kg) d. Bulbar palsy e. Autonomic cardiovascular instability N.B: Sedation and neuromuscular blockade should be avoided in ventilated patients because they obscure the course of the illness.

37. GBS Management Risk factors for respiratory failure in GBS: Cranial nerve involvement. Short time from preceding respiratory illness. Rapid progression over less than 7 days. Elevated CSF protein in the first week. Severe weakness: unable to lift elbows above the bed unable to lift head above the bed unable to stand. 20% of children with GBS require mechanical ventilation for respiratory failure.

38. Special Therapy Immune modulatory therapy: Intravenous Immunoglobulins Plasmapheresis IVIG is preferred to plasma exchange in children because of the relative safety and ease of administration, although it has not been shown to have better results. Both therapies have been shown to shorten recovery time by as much 50%. Combining plasma exchange and IVIG neither improved outcomes nor shortened the duration of illness. IVIG and plasma exchange are not recommended for ambulatory children with GBS who have mild disease or for children whose symptoms have stabilized.

39. IVIG Regimens Several IVIG regimens have been utilized. One regimen includes daily IVIG for 5 days at a dose of 0.4 gm/kg/day, which results in an improvement within a mean of 2 to 3 days after the start of therapy. Other authors use 2 gm/kg of IVIG given as a single dose or 1gm/kg/day for 2 days. One study compared the outcome of 0.4 gm/kg/day given for 3 days versus 6 days. In that study, the 6 days of IVIG was superior when “time to walking” was used as an endpoint. When comparing treatments of 1gm/kg for 2 days versus 0.4gm/kg over 5 days, no significant difference in the effectiveness was noted in the 2 treatment regimens. However, early “relapses” were more frequently observed in the shorter treatment group.

40. Plasmapheresis Studies in children indicate that plasmapharesis may decrease the severity and shorten the duration of GBS. It is most beneficial when started within 7 days of the onset of symptoms but is still beneficial in patients treated up to 30 days after disease onset.

41. Management…cont Corticosteroids are not effective and not indicated Interferon-ß reported to be beneficial in individual cases, but its safety and efficacy have not been established in clinical trials.

42. Prognosis In general, the prognosis in affected children is better than adults. Recurrences are uncommon but can occur in children. Some may have a chronic progressive course, whereas others may show recurrences or relapses. At long-term follow up, 93% were free of symptoms, and the remainder were able to walk unaided. 50% are ambulatory by 6 mo, 70% walk within ayear of onset of the disease. Mortality is approximately 3 to 4%, and usually is secondary to autonomic dysfunction and respiratory failure.

43. Poliomyelitis polio= gray matter Myelitis = inflammation of the spinal cord. Poliomyelitis is caused by a virus that attacks the nerve cells of the brain & spinal cord although not all infections result in sever injuries and paralysis.

44. Poliomyelitis: Etiology Etiology: Caused by a poliovirus. 3 serotypes of poliovirus (genus Enterovirus ). Type 1 most frequently associated with epidemics. Types 2 and 3 usually associated with vaccine- associated paralytic polio (VAPP).

45. In 1% of cases virus invades CNS. Multiplies and destroys anterior horn cells. In severe cases, poliovirus may attacks motor neurones in brainstem, leading to difficulty in swallowing, speaking and breathing.

46. Poliovirus: Pathogenesis Incubation period of 7 to 14. Transmitted by oral-fecal contact. Person-to-person spread is the most common means of transmission, followed by contaminated water. During epidemics, it also may be transmitted by pharyngeal spread. Poliovirus initially infects the GI tract. It may spread to lymph nodes and rarely to CNS. The mechanism of spread of poliovirus to the CNS is not well understood.

47. Epidemiology 3 months-16 years; rarely adults Predominant sex: Male = Female Improved sanitation led to many less infants being exposed to poliovirus. When exposure occurred later and the individuals were not protected by maternal antibodies, there were polio epidemics.

48. Poliomyelitis: Incidence & Prevalence Incidence: Now rare; present in: (a) Endemic settings. (b) Small outbreaks in areas where polio eradication has occurred. (c) Rarely as vaccine-associated paralytic polio (VAPP) cases. Prevalence:  Endemic countries: Afghanistan, India, Nigeria and Pakistan

49. Poliomyelitis: Risk Factors Immune deficiency Pregnancy Poor sanitation and hygiene  Poverty  Unimmunized status, especially if <5 years Tonsillectomy: a risk factor for bulbar paralysis. Intramuscular injections or truama Genetics: No genetic susceptibility has been identified.

50. Clinical Presentation The majority of patients are asymptomatic. ~5% develop symptoms. ~10% will show signs and symptoms of a minor GI illness, including fever, malaise, nausea, and vomiting. 0.1% develop the paralytic form of poliomyelitis. Symptoms of poliomyelitis always CNS specific.

51. Clinical Presentation…cont CNS manifestations: Weakness: Vary from one muscle or group of muscles, to quadriplegia. Proximal muscles: legs more commonly than arms. Typically worsens over 2 to 3 days but sometimes can progress for up to a week. Bulbar involvement: 5 – 35% producing dysphagia, dysarthria, and difficulty handling secretions. There may be encephalitis, usually in infancy. Cardiovascular & Resp. symptoms…bulbar poliomyelitis

52. Physical Exam: Significant motor loss on affected side or limb. Meningeal signs may be present in minor illness or early phases of paralytic polio. Decreased deep tendon reflexes. Muscle atrophy of affected areas. Tone is reduced: asymmetric The sensory examination is normal.

53. Poliomyelitis: Diagnosis  Based on the clinical presentation. Cerebrospinal Fluid: Leukocytosis, Increased protein, Normal glucose. Virus recovery from stool, throat washing, blood. Virus recovery from stool is essential to diagnosis. Obtain stool, blood and throat samples for viral serology, demonstrating a four fold rise in IgG is helpful but not always easy. Positive IgM is diagnostic. Polymerase chain reaction amplification of poliovirus RNA from CSF or serologically, by comparing viral titers in acute and convalescent sera.

54. Diagnosis…cont  Electrodiagnostic investigations reveal normal sensory nerve studies. Motor nerve studies: show normal to mildly slowed conduction velocities and low to normal amplitudes. MRI may be helpful to evaluate involvement of anterior horn of the spinal cord or other findings.

55. Treatment No definitive treatment. Mainly supportive: pain relief and physical therapy for muscle spasms. Patients with bulbar involvement require close monitoring of cardiovascular status and autonomic dysfunction. Mechanical ventilation: Respiratory failure. Treatment of complications.

56. Poliomyelitis: Complications Urinary tract infection Skin ulcers Traumatic injuries to affected limb(s) Atelectasis & Pneumonia Myocarditis Postpoliomyelitis progressive muscular atrophy. Postpoliomyelitis motor neuron disease.

57. Clinical Course & Outcome About two-thirds of patients with acute flaccid paralysis do not regain full strength. The more severe the acute weakness, the greater the chance of residual deficits, Bulbar squeals are rare. The mortality was 5 to 10% in the era of epidemics, and approached 50% for those with bulbar involvement because of cardiovascular and respiratory complications.

58. PREVENTION OF POLIOMYELITIS

59. Polio Vaccination  Jonas Salk created the inactivated poliovirus vaccine (IPV), using killed virus in 1952. The Sabin oral poliovirus vaccine (OPV), using live attenuated virus, proved successful in 1960. In areas of the world where polio is endemic, primary immunization is still performed with Sabin OPV. But, because it causes polio in one out of 2.5 million cases, it has been replaced by the Salk IPV in countries without polio, including the United States and most of Europe.

60. Polio Vaccination  Multiple doses required to achieve high humeral conservation rates against all virus types Babies are given 4 doses through out their infancy. Adolescents and adults should get vaccinated as well. Adolescents younger than 18 should receive the routine four doses. You should get it if you travel outside places where polio is still epidemic.

61. Transverse Myelitis Transverse myelitis is a condition characterized by rapid development of both motor and sensory deficits . Transverse Myelitis

62. Pathophysiology Presumed autoimmune mediated inflammation and demyelination of the spinal cord. Postinfectious etiology largely predominates in children An immunization history within the few weeks preceding neurologic difficulties. Transverse Myelitis

63. Classical History Mean age of onset is 9 years. Symptoms progress rapidly, peaking within 2 days. Usually level of myelitis is thoracic. Asymmetrical leg weakness, sensory level and early bladder involvement. Recovery usually begins after a week of onset. Transverse Myelitis

64. Physical Examination Tenderness over the spine may point to trauma or infection . Increased tone, spastic weakness, legs more than arms Reflexes are usually brisk, with positive Babinski sign. Sensory ataxia, a sensory level. Sphincter dysfunction. Transverse Myelitis

65. Associated Conditions Connective tissue diseases, e.g. SLE, JRA, sarcoidosis , vasculitis … Rarely seen in association with metabolic causes of myelopathy such as vitamin B12 deficiency. Transverse Myelitis

66. DIAGNOSTIC CRITERIA FOR TRANSVERSE MYELITIS Bilateral (not necessarily symmetric) sensorimotor and autonomic spinal cord dysfunction Clearly defined sensory level. Progression to nadir of clinical deficits between 4 hours and 21 days after symptom onset. Demonstration of spinal cord inflammation: cerebrospinal fluid pleocytosis or elevated IgG index or MRI revealing a gadolinium-enhancing cord lesion. Exclusion of compressive, postradiation , neoplastic , and vascular causes. Transverse Myelitis

67. Treatment Symptomatic management of bowel and bladder dysfunction. Management of respiratory, cardiovascular & autonomic dysfunction. IV methylprednisolone . IV immunoglobulin (IVIG) or plasmapheresis . Cyclophosphamide has been reported to be useful in myelitis associated with systemic inflammatory diseases Physical and occupational therapy may help promote functional recovery and prevent contractures . Transverse Myelitis

68. Prognosis 50% make a full recovery within 3 to 6 months. 40% recover incompletely. 10% don’t recover. Older age, increased deep tendon reflexes, and presence of Babinski sign may indicate better course. Rapid progression, back pain, and spinal shock predict poor recovery. Transverse Myelitis

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